where \(\Gamma _{h_B}\)  is the total decay width of \(h_B\) , \(s\)  is the square of the center-of-mass energy and \(C_{gg}\)  is the gluonic PDF contribution.
Using MSTW2008 PDFs at NLO [1]}, \(C_{gg}=2137\)  for \(\sqrt{s}= [13]{TeV}\)  and \(M_{h_B} = [750]{GeV}\) . Working in
the most optimistic scenario where the decay is dominated by the decay into two gluons, one finds
\(\sigma (pp \rightarrow h_B) \times \text{BR}(h_B \rightarrow \gamma \gamma ) \approx 6.6 \times 10^{3}\, \Gamma (h_B \rightarrow \gamma \gamma ) \frac{\text{fb}}{\text{GeV}}.\) 
